动脉粥样硬化是血管壁的慢性炎症性疾病，而血管壁中层的平滑肌细胞在血管炎症反应过程中的作用尚不明确。我们研究显示，老龄动脉粥样硬化模型Apoe-/-小鼠腹主动脉外膜形成类似于淋巴结的细胞集聚，称之为动脉三级淋巴组织，而当血管中膜平滑肌细胞淋巴毒受体(LTbR)缺失后，Apoe-/-小鼠外膜三级淋巴组织形成受到抑制，而内膜斑块增大并伴随斑块中磷酸化的mTOR和S6蛋白激酶增高。申请项目拟以血管内膜，中膜和外膜的免疫学改变为研究对象，利用已建立的动脉细胞制备技术，单细胞水平测序及流式细胞等技术，研究血管平滑肌细胞LTbR如何调控内膜炎症反应和中膜形态及功能变化，并影响PI3K-Akt-mTOR 信号通路，以及是否通过调控外膜三级淋巴组织的形成，而最终影响内膜动脉粥样硬化斑块的生成，从而阐释血管平滑肌细胞LTbR信号通路的血管免疫学效应，为心血管疾病新的治疗策略的制定提供理论基础。

Atherosclerosis is a chronic inflammatory disease of vascular wall. As the media layer, the role of vascular smooth muscle cells during the inflammatory response is unclear. Our previous data demonstrated that the immune cells aggregate occur in the adventitia of abdominal aorta in aged atherosclerotic Apoe-/- mice. We called the cell aggregates as Aorta Tertiary Lymphoid Organs. The aged Apoe-/- mice with lymphotoxin beta receptor (LTbR) deficiency in the smooth muscle cells showed the inhibition of tertiary lymphoid organ development, while the increase of intima plaque with the enhanced protein expression of phosphated mTOR and S6 in the plaque. In the present application, we propose to focus on the immunological changes during the inflammatory responses in the vascular intima, media and adventitia. By using the set-up technologies of cell preparation from aorta, sequencing at the single-cell level, and the flow cytometry and so on,we will address how the smooth muscle cell LTbR signaling regulates the inflammatory responses in the intima, the morphological and functional changes of the media, and the affects on the expression of PI3K-Akt-mTOR signaling pathway, and whether it regulates the intima plaque development through regulating the formation of adventitial tertiary lymphoid organs. This study will address the mechanism of mediating vascular immunology by LTbR signaling pathway, and provide the theory basic for developing a new therapy for treatment of vascular diseases.